Why might your vote be more fitting elsewhere? You're
not voting -- on the anon or the dud monk, you're voting
-- on the post. Reputation is supposed to be a way
to gauge the value of a post.

Also, there are rumours that posts which sink
too low will be removed, so --ing such posts could actually
be a suitable way to remove garbage.

Update: in reply to AgentM's reply:
There is a way to let Vroom know something should be
deleted. It's the 'consider node' option in the
approval nodelet. It just doesn't appear to be
completely functional yet.